Benign Tumors Flashcards
Definition of benign tumors of the jaw (3)
- Slowly growing
- Spread by direct extension and not by metastases
- Tend to resemble the tissue of origin
- Example: Ameloblastoma is composed of cells that resemble ameloblasts
8 clinical features of benign tumors of the jaw
- Slowly growing
- Painless
- Sewlling (may present as bone expansion)
- Do not metastasize
- Not life threatening
- Detected by enlargement of the jaws
- Found by chance during radiographic examination
- Lack of tooth eruption
Location of odontogenic benign tumors
Alveolar process
Location of vascular and neural benign lesions
Originate inside the mandibular canal
Location of cartilaginous benign tumors
Where redisual cartilaginous cells lie (around the mandibular condyle)
Describe the periphery and shape of benign tumpors
- Smooth appearance of the borders
- Well defined, sometimes corticated (sclerotic)
Describe the internal structure of benign tumors (3)
- Radiolucnet, radiopaque, mixture of radiolucent and radiopaque tissues
- Bony septa (unilocular or multilocular)
- Internal pattern is characteristic for specific types of tumors
Describe the effect on surrounding structures of a benign tumor (4)
- Outer cortical plate expansion
- Tooth displacement
- Root resorption
- Displacement of the mandibular canal
Percentage of oral tumors that odontogenic tumors comprise
1 - 15%
3 categories of odontogenic tumors
- Epithelial tumors
- Mixed tumors (odontogenic epithelium and odontogenic ectomesenchyme)
- Mesenchymal tumors (odontogenic ectomesenchyme)
4 types of odontogenic epithelial tumors
- Ameloblastoma
- Calcifying epithelial odontogenic tumor
- Adenomatoid odontogenic tumor
- Keratocystic odontogenic tumor
2 types of ameloblastoma
- Multicystic variant
- Unicystic variant
Most frequent odontogenic tumor
Ameloblastoma
3 general characteristics of ameloblastoma
- Neoplasm of odontogenic epithelium
- Agressive but benign growth characteristics
- Arises from rests of the dental lamina and dental organ
8 clinical features of ameloblastoma
- 30 - 60 years w/ average age ~40
- No sex predilection
- Frequently discovered during a routine radiographic exam
- Increasing facial asymmetry
- Mucosa over the lesion is normal
- Teeth in the involved resion may be displaced
- Painless
- Risk of local recurrence (requires aggressive surgical resection)
Describe the radiographic location of ameloblastoma
- Most (85%) develop in the mandible
- Molar-ramus region
- Third molar area of the maxilla
- Can originate in an occlusal position to a developing tooth
Describe the radiographic periphery and shape of ameloblastoma
- Well-defined
- Curved outline
- Small lesions are indistinguishable from a cyst
Describe the radiographic internal structure of ameloblastoma
- Radiolucent
- Presence of curved bony septa (soap bubble pattern)
- Numerous small loculations (honeycomb pattern)
- Unilocular or multilocular aspect
4 effects on surrounding structures of ameloblastoma
- Tooth displacement
- Tooth resorption
- Bone expansion
- Displacement of the mandibular canal
Differentiate between odontogenic myxoma and ameloblastoma
Odontogenic myxoma is not as expansible as ameloblastoma
3 differential diagnoses for ameloblastoma
- Odontogenic keratocyst
- CGCG
- Odontogenic myxoma
Differentiate between ameloblastoma and odontogenic keratocyst
Less marked expansion and usually in posterior aspect of bone in association with impacted teeth
Differentiate between CGCG and ameloblastoma
CGCG = younger age group, wispy ill-defined septa
Usually localized to area anterior to 1st molar on mandible
Differentiate between odontogenic myxoma and ameloblastoma
Odontogenic myxoma is not as expansible as ameloblastoma
Treatment for ameloblastoma
Surgical resection with margins and potentially bone transplant subsequently (esp. if extensive)
4 general clinical features of unicystic ameloblastoma
- May develop as a single entity
- May derived from the epithelial linign of a dentigerous cyst
- Occur in younger age group (average age = 23 yr)
- Most frequent location = posterior body of the mandible (3rd molar)
Describe the radiographic features of unicystic ameloblastoma (3)
- Radiolucent lesion
- Well-defined
- Often associated with 3rd molar
Differential diagnosis for unicystic ameloblastoma
Dentigerous cyst
Differentiate between unicystic ameloblastoma and dentigerous cyst
Dentigerous cyst identified via attachment of cyst to the CEJ of 3rd molar (unlike UA)
Describe the general flow chart of differentiating between tumors and cysts
3 general characteristics of calcifying epithelial odontogenic tumor
- Pindborg tumor
- Rare (account for about 1% of odontogenic tumors)
- Originate from stratum intermedium of the enamel organ
5 clinical features of calcifying epithelial odontogenic tumor
- Average age 40 yr
- No sex predilection
- Inraosseous location
- Asymptomatic, jaw expansion (painless swellling)
- Palpation reveals hard tumor
Describe the radiographic location of calcifying epithelial odontogenic tumor
- Predilection for the mandible (2:1)
- Premolar-molar area
- Frequent association with an unerupted or impacted tooth (50%)
Describe the radiographic appearance of calcifying epithelial odontogenic tumor (4)
- Well-defined lesion
- Unilocular or multilocular with mixed radiolucent-radiopaque lesion
- Appearance of radiopacities close to the crown of the impacted tooth
- Tooth displacement, expansion of the jaw
4 differential diagnoses for Calcifying epithelial odontogenic tumor
- Dentigerous cysts (if completely radiolucent interior)
- Adenomatoid odontogenic tumor
- Ameloblastic fibro-odontoma
- Calcifying odontogenic cyst
3 general characteristics of adenomatoid odontogenic tumor
- Account for 3 - 7 % of all oral tumors
- Non-aggressive
- Originates from enamel organ epithelium
5 clinical features of adenomatoid odontogenic tumor
- 70% occur in the second decade
- 90% appear before 30 years
- Female predilection (2:1)
- Slow growing tumor
- Painless swelling
2 types of adenomatoid odontogenic tumors
- Folicular type (associated with an embedded impacted tooth; in image)
- Extrafollicular type (no embedded tooth)
Describe the radiographic location of adenomatoid odontogenic tumor
- 75% occur in the maxilla
- Incisor-canine-premolar region
- Frequent association with an impacted tooth (i.e. canine)
Describe the radiographic periphery of adenomatoid odontogenic tumor
Well-defined border
Describe the radiographic internal structure of adenomatoid odontogenic tumors
- Radiolucent, unilocular
- Radiopacities in 2/3 of cases (snowflakes)
Describe the MRI of adenomatoid odontogenic tumor
- Homogenous hypersignal
- Thick rim enhancement
2 differential diagnoses for Adenomatoid odontogenic tumor
When tumor is completely radiolucent and is associated with an impacted tooth, difficult to differentiate with dentigerous cyst and odontogenic keratocyst
2 ways to differentiate between Adenomatoid odontogenic tumor and dentigerous cyst
- Calcifications may be present in Adenomatoid odontogenic tumor (snowflakes)
- DC = attachment to the CEJ
3 types of odontogenic mesenchymal tumors
- Odontogenic myxoma
- Cementoblastoma
- Central odontogenic fibroma
Define odontogenic myxoma
Benign, intraosseous, non-encapsulated neoplasm, that tend to infiltrate the surrounding cancellous bone
NOTE: Rare (3 - 6% of odontogenic tumors)
Origin of odontogenic myxoma
Mesenchymal portion of the dental papilla
5 clinical features of odontogenic myxoma
- 25 - 30 years
- No sex predilection
- Slow growing
- Painless swelling
- Risk of local recurrence (20%)
Radiographic location of odontogenic myxoma
- Predilection for the mandible (3:1)
- Premolar-molar area
Describe the periphery and shape of odontogenic myxoma (radiograph)
- Well-defined with corticated margin
- Often poorly defined, especially in the maxilla (i.e. image)
Describe the radiographic internal structure of odontogenic myxoma
- Majority of lesions = mixed radiolucent-radiopaque internal pattern
- Curved and coarse septa –> multilocular appearance
3 effects of odontogenic myxoma on surrounding structures
- Tooth displacement
- Bone expansion
- Expansion into sinus
3 differential diagnoses for odontogenic myxoma
- Ameloblastoma
- CGCG
- Osteosarcoma
4 general characteristics of cementoblastoma
- Slow growing mesenchymal neoplasm
- Composed of cementum-like tissue and abnormal bone
- Histologic characteristics are similar to those of osteoblastoma
- Often develops with permanent teeth
6 clinical features of cementoblastoma
- Relatively young patients (less than 30 yrs)
- No sex predilection
- Solitary lesion
- Slow growing
- Involved tooth is vital and often painful
- Relived by anti-inflammatory drugs
2 effects of cementoblastoma on surrounding structures
- Root resorption
- Bone expansion
Describe the periphery and shape of cementoblastoma
- Well-defined radiopacity with corticated margin
- Radiolucent band just inside the cortical border
Location of cementoblastoma
- More commonly in mandible
- More commonly associated with a premolar or a first molar
3 differential diagnoses for cementoblastoma
- Focal periapical cemental dysplasia
- Periapical sclerosing osteitis
- Dense bone island
Differentiate between focal periapical cemental dysplasia and cementoblastoma
More irregular outline with PCD + localized in anterior mandibular teeth
How is cementoblastoma different from its differential diagnoses of periapical sclerosing osteitis and dense bone island
Both differentials lack soft tissue capsule
3 general characteristics of central odontogenic fibroma
- Rare odontogenic neoplasm
- Contains mature fibrous tissue
- May contain calcifications that resemble dysplastic dentin, cementum or osteoid tissue
4 clinical features of central odontogenic fibroma
- Average age = 4 yrs
- Female preponderance
- Asymptomatic
- Painless swelling
Location of central odontogenic fibroma
- Occur more commonly in the mandible
- Premolar-molar area
Radiographic periphery and shape of central odontogenic fibroma
Well-defined
Describe the radiographic internal structure of central odontogenic fibroma
- Radiolucent
- Fine internal septa
2 effects of central odontogenic fibroma on surrounding structures
- Tooth displacement and root resorption
- Bone expansion
2 differential diagnoses for central odontogenic fibroma
- Odontogenic myxoma
- CGCG
3 types of mixed odontogenic tumors
- Amelobastic fibroma
- Ameloblastic fibro-odontoma
- Odontoma
4 general characteristics of ameloblastic fibroma
- Benign mixed odontogenic tumor
- Proliferation of epithelium resembling dental lamina
- Proliferation of mesenchymal component resembling dental papilla
- Enamel, dentin and cementum are not formed in this tumor
5 clinical features of ameloblastic fibroma
- Occur between 5 - 20 yrs
- No sex predilection
- Slow growing expansion
- Painless swelling
- Discovered on a routine dental RX
Location of ameloblastic fibroma
- Premolar-molar area of mandible
- Often associated with an unreupted tooth (75%)
- Located occlusal to the tooth
Describe the radiographic periphery and shape of ameloblastic fibroma
- Well-defined radiopacity with corticated margin (like a cyst)
- Unilocular, radiolucent lesion
3 effects on surrounding structures by ameloblastic fibroma
- Associated unerupted tooth may be displaced in an apical direction
- Root resorption
- Bone expansion
3 differential diagnoses of ameloblastic fibroma
- Hyperplastic follicle
- Dentigerous cyst
- Ameloblastoma
How to differentiate dentigerous cyst from ameloblastic fibroma
Attachment of DC at CEJ
Define ameloblastic fibro-odontoma
- Lesion very similar to ameloblastic fibroma
- Ameloblastic fibroma with collections of enamel and dentin
- Considered to be an early stage of a developing odontoma
5 clinical features of ameloblastic fibro-odontoma
- Commonly observed in young patients (<10 yrs)
- No sex predilection
- Slow growing
- Painless swelling
- Often associated with a missing tooth
Effect of ameloblastic fibro-odontoma on surrounding structures
Apical tooth displacement
Radiographic periphery and shape of ameloblastic fibro-odontoma
Well-defined sclerotic border
Radiographic internal structure of ameloblastic fibro-odontoma
- Mixed
- Large lesion may present extensive calcifications
Location of ameloblastic fibro-odontoma
- More commonly located in posterior mandible
- Center of lesion is occlusal to a developing tooth
3 differential diagnoses of ameloblastic fibro-odontoma
- Ameloblastic fibroma
- Odontoma (complex odontoma)
- CEOT
Differentiate between ameloblastic fibro-odontoma and odontoma (complex odontoma)
AFOs have a greater soft tissue band (radiolucent)
Differentiate between ameloblastic fibro-odontoma and CEOT
Calcifications are less dense in CEOT than those in ameloblastic fibro-odontoma
Define odontoma
- Characterized by the production of mature enamel, dentin, cementum, and pulp tissue
- Considered to be a hamartoma and not a true tumor
- Limited lesion
- Well-differentiated tooth tissue
- Slow-growing lesion
2 types of odontoma
- Complex odontoma (agglomerate of all dental tissues)
- Compound odontoma (numerous tooth-like structures known as denticles)
6 clinical features of odontoma
- Often interfere with eruption of permanent teeth –> delayed eruption of adjacent teeth or retained primary teeth
- Compound odontoma = twice as common as complex type
- Most occur in the second decade
- Commonly observed in young patients (<10 yrs)
- No sex predilection
- Discovered on routine dental RX
Location of compound odontoma
Most occur in anterior maxilla (62%)
Location of complex odontoma
Molar area of mandible mostly (70%)
Radiographic appearance of odontoma
Well-defined sclerotic border
Radiographic internal structure of odontoma (4)
- Radiopaque
- Compound type = number of toothlike structure of denticles
- Complex = irregular mass of calcified tissue
- Degree of opacity is equivalent to adjacent tooth structure
3 effects of odontoma on surrounding structures
- Interfere with normal eruption of teeth
- Most associated with abnormalities such as impaction, malpositioning and diastema
- Large complex odontoma may cause cortical expansion
4 differential diagnoses for odontoma
- Ameloblastic fibro-odontoma
- Cemento-ossifying fibroma
- Periapical cemental dysplasia
- Dense bone islands
Differentiate between odontoma and cemento-ossifying fibroma
Odontoma are often associated with unerupted teeth and are more radiopaque
Differentiate between odontoma and periapical cemental dysplasia
Periapical cemental dysplasia features multiple lesions centered on the periapical regoin of teeth
Differentiate between odontoma and dense bone islands
Dense bone islands do not present a soft capsule